During the manufacture of products, particularly large products such as aircraft, assembly holes must be drilled in two workpieces to be mated together. There are two general techniques for drilling holes in such workpieces. In the first technique, the holes may be separately drilled in each workpiece and then the separate workpieces are mated together for assembly. This technique can introduce errors with alignment, size, and/or orientation when the layers are assembled together. These errors can be caused by a lack of precision in the device used to drill such holes, e.g., a computer numerical control (“CNC”) machine or a computer-controlled robot arm.
In the second technique, called match drilling, the two workpieces are temporarily fastened together and each hole is drilled once through the two mated workpieces. The workpieces are then disassembled for deburr and inspection before being reassembled and fastened permanently. This process is very time consuming, particularly when the workpieces are large parts, e.g., aircraft parts, because the workpieces must be assembled twice for a single join.
Accordingly, there is a need for an improved system and method for precisely drilling holes in mating workpieces which overcomes the problems identified above.